noun
A loanword used for decorative items, ornamentation, or festive embellishments, similar to English 'decoration'.
クリスマスのデコレーションを部屋に飾った。
I put up Christmas decorations in the room.
ケーキのデコレーションがとてもきれいだ。
The cake decoration is very beautiful.
飾り is the native Japanese word for decoration or ornament, often used for physical adornments. デコレーション is a loanword with a slightly more modern or Western feel, commonly used for festive or cake decorations.
Borrowed from English 'decoration'.